Water repellent film and component for vehicle including the film

ABSTRACT

A water repellent film ( 200 ) according to the present invention includes a first layer ( 10 ) having a plurality of fine protrusions ( 100 ) on the surface thereof, a second layer ( 20 ) covering the fine protrusions ( 100 ) and having a water repellent property, and a third layer ( 30 ) provided on the surface of the first layer ( 10 ) on the opposite side of the fine protrusions ( 100 ). When a modulus of elasticity of the first layer ( 10 ) is defined as E1, a modulus of elasticity of the second layer ( 20 ) is defined as E2, and a modulus of elasticity of the third layer ( 30 ) is defined as E3, a definition of E2&gt;E1&gt;E3 is fulfilled. Accordingly, the water repellent film having excellent resistance to abrasion in which a fine structure is not easily abraded and damaged by an external friction force or the like can be obtained.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No.13/202,853, filed on Aug. 23, 2011, which is the National Stage ofApplication No. PCT/JP2010/059222; filed on May 31, 2010, the entirecontents of all of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a film having a water repellentfunction. More particularly, the present invention relates to a waterrepellent film capable of preventing abrasions and damages due to anexternal friction force caused to fine protrusions formed on the surfaceof the film, and relates to a component for a vehicle including thefilm.

BACKGROUND ART

A fine structure has fine protrusions formed on the surface thereof, andhas a water repellent/hydrophilic function and an antireflectionfunction depending on a material and a dimensional configuration of thefine structure. Therefore, surfaces of various substrates applied withsuch a fine structure can have an antireflection function with respectto light and a water repellent function to prevent adhesion of liquid,such as water in particular. For example, in order to provide such anantireflection function, a fine structure is favorably used for opticalelements such as lenses for mechanical equipment (for example, refer toPatent Literature 1).

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent Unexamined Publication No.2005-31538

SUMMARY OF INVENTION

However, in the case where the fine structure described in PatentLiterature 1 is applied to a member such as a window panel of a vehiclethat is subjected to various environmental conditions, when dirt adheredto the surface of the member because of rain or the like is removed witha cloth, the fine structure is easily abraded and damaged. Thus, thereis a problem with a water repellent property of the fine structure thatis impaired in a short period of time.

The present invention has been made in view of such a conventionalproblem. It is an object of the present invention to provide a waterrepellent film having excellent resistance to abrasion, in which a finestructure is not easily abraded and damaged by an external frictionforce such as a removal of dirt with a cloth on a surface thereof, and acomponent for a vehicle including the film.

A water repellent film according to the embodiment of the presentinvention includes: a first layer having a plurality of fine protrusionson a surface thereof; a second layer covering the fine protrusions andhaving a water repellent property; and a third layer provided on asurface of the first layer on an opposite side of the fine protrusions.When a modulus of elasticity of the first layer is defined as E1, amodulus of elasticity of the second layer is defined as E2, and amodulus of elasticity of the third layer is defined as E3, a definitionof E2>E1>E3 is fulfilled.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a partial cross-sectional view showing one example of a waterrepellent film according to the embodiment of the present invention.

FIG. 2 is a schematic view showing a configuration example of fineprotrusions in a water repellent film according to the embodiment of thepresent invention.

FIG. 3 is a schematic view showing a structural example of fineprotrusions in a water repellent film according to the embodiment of thepresent invention.

FIG. 4 is a schematic view explaining input conditions in a compressivedirection and in a shear direction with respect to fine protrusions in awater repellent film according to the embodiment of the presentinvention.

FIG. 5 is a schematic view showing a mechanism of a water repellentproperty in a water repellent film according to the embodiment of thepresent invention.

FIG. 6 is a schematic view showing elongation behavior of each layer ina case in which a water repellent film according to the embodiment ofthe present invention is attached to a three-dimensional curved surface.

DESCRIPTION OF EMBODIMENTS

A description will be made below in detail of a water repellent film anda component for a vehicle including the film according to the presentinvention with reference to the drawings. Note that, the dimensionalratios in the drawings are exaggerated for convenience of explanation,and may be different from the actual ratios. In the present description,“%” with regard to concentrations, contents and the like represents amass percentage unless otherwise specified.

[Water Repellent Film]

A water repellent film 200 according to the embodiment of the presentinvention includes a first layer 10 having a plurality of fineprotrusions 100 on the surface thereof, and a second layer 20 coveringthe surfaces of the fine protrusions 100 and having a water repellentproperty. In addition, a third layer 30 is provided on the surface ofthe first layer 10 on the opposite side of the surface provided with thefine protrusions 100. When a modulus of elasticity of the first layer 10is defined as E1, a modulus of elasticity of the second layer 20 isdefined as E2, and a modulus of elasticity of the third layer 30 isdefined as E3, the definition of E2>E1>E3 is fulfilled.

FIG. 1 shows the water repellent film 200 according to the embodiment ofthe present invention. The water repellent film 200 has the fineprotrusions 100 formed into a frustum shape. Examples of theconfiguration of the fine protrusions 100 to be favorably used include afrustum shape such as a circular truncated cone and a truncated pyramid,and a cone or pyramid shape. In addition, other configurations such as adeformed cone shape such as a bell shape and an acorn shape, a deformedpyramid shape having curved side surfaces, a round-tipped shape, and ashape inclined from a center line, may be applied to the fineprotrusions 100. FIG. 2 shows examples of the cross-sectionalconfiguration that the fine protrusions 100 may employ in the waterrepellent film according to the embodiment of the present invention.

Examples of a bottom surface configuration of the fine protrusions 100to be favorably used include a polygonal shape and a substantiallycircular shape. In addition, other shapes such as a star shape and anoval shape may be used. The water repellent film of the presentinvention may include concave portions 101 between the fine protrusions100 as long as the fine protrusions 100 are two-dimensionally alignedwith a predetermined pitch, as shown in FIG. 3. In the presentdescription, as shown in FIG. 3(a), when it is assumed that there is asurface B′ passing through bottoms 102 of the respective concaveportions 101, each section on the surface B′ sectioned by the bottoms102 of the concave portions 101 surrounding the fine protrusions 100 isdefined as a bottom surface of the respective fine protrusions 100.Similarly, in the case where base portions 103 of the fine protrusions100 have curved surfaces as shown in FIG. 3(b), when it is assumed thatthere is the surface B′ passing through bottoms 104 between therespective base portions 103 of the fine protrusions 100, each sectionon the surface B′ sectioned by the bottoms 104 between the base portions103 surrounding the fine protrusions 100 is defined as a bottom surfaceof the respective fine protrusions 100.

A pitch A of the respective fine protrusions 100 is preferably 50 μm orless. When the pitch A between the fine protrusions 100 adjacent to eachother is more than 50 μm, an effective water repellent property ofvarious window panels using such a water repellent film is not easilyexerted. Namely, since water droplets of a drizzly rain have a size ofapproximately 50 μm, water droplets are infiltrated in gaps between thefine protrusions, and the water droplets are not easily removed from thesurface of the water repellent film. However, when the surface of thesecond layer 20 formed on the fine protrusions 100 is subjected to waterrepellent treatment using a water repellent material as described below,the water repellent film may have a high water repellent property evenwhen the pitch A is more than 50 μm. Note that, in the presentdescription, the pitch A of the respective fine protrusions 100represents a distance between each barycenter in the bottom surfaces ofthe fine protrusions 100 adjacent to each other.

When an antireflection function is applied to the water repellent film200, the pitch A of the respective fine protrusions 100 is preferably380 nm or less. Namely, the pitch A of the fine protrusions 100 ispreferably equal to or less than a wavelength of visible light which isnot more than 380 nm to 750 nm. When the pitch A exceeds 380 nm, thevisible light is partially diffused or diffracted by the fineprotrusions 100, and accordingly, a reflectance of the light may becomelarge. The pitch A of the respective fine protrusions 100 is morepreferably 150 nm or less. When the pitch A is 150 nm or less, thesurface roughness of the water repellent film is not more than anaverage surface roughness of human nails. Therefore, performance ofabrasion resistance to scratch of nails is effectively exerted onvarious window panels using the water repellent film. As describedbelow, a high water repellent property is exerted on the water repellentfilm when the fine protrusions 100 are formed on the surface of thewater repellent film so as to increase a surface area, and when gaps fortrapping air are formed between the fine protrusions 100 adjacent toeach other. Consequently, the pitch A of the fine protrusions 100 ispreferably 50 nm or more.

In the first layer 10, a height H of the fine protrusions 100 ispreferably 100 nm or more. When the height H of the fine protrusions 100is less than 100 nm, an antireflection effect may be decreased. Inaddition, when the height H of the fine protrusion 100 is too low, it ishard to trap air between the fine protrusions 100, which may cause adecrease of a water repellent property. On the other hand, when theheight H of the fine protrusions 100 is too high, the fine protrusions100 are easily fractured and at the same time moldability may bedecreased. Thus, the height of the fine protrusions 100 is preferably600 nm or less. It is to be noted that, when the surface of the secondlayer 20 is subjected to water repellent treatment as described above, ahigh water repellent property may be exerted even when the height H isless than 100 nm. The height of the fine protrusions 100 is a distancebetween each bottom 104 of the fine protrusions 100 and each tip of thefine protrusions 100 in the perpendicular direction to the bottomsurface B′. When the concave portions 101 are provided between therespective fine protrusions 100, the height as indicated by thereference symbol H in FIG. 3 is a distance each bottom (the deepestpart) 102 of the concave portions 101 and each tip of the fineprotrusions 100 in the perpendicular direction to the bottom surface B′.

In the water repellent film 200, when the fine protrusions 100 areformed into a cone or pyramid shape, or a truncated cone or truncatedpyramid shape (tapered shape), and two-dimensionally aligned with thepitch A of 380 nm or less, a dimension of the fine asperity on thesurface cannot be recognized by visible light. As a result, colorationdue to interference of light disappears, and therefore, the waterrepellent film can be used as a transparent material. Moreover, sincereflection of surrounding scenery on the film can be decreased due to anantireflection effect, the water repellent film can be favorably usedfor window panels for vehicles, ships and vessels, and aircraft.Further, since the gaps between the fine protrusions 100 are elongated,and water infiltration because of impact of water droplets is prevented,the water repellent film exerts a superhydrophobic property with noadhesion of water droplets such as rain, depending on the materials tobe selected.

The dimension of the fine protrusions 100 in the water repellent film ofthe present invention is a nanometer order as described above. Thus, theconfiguration and pitch of the fine protrusions 100 do not have acomplete geometric configuration, but vary to some extent because of amanufacturing restriction. However, the there is no limitation in scopeof the present invention even if variations of the configuration andpitch of the fine protrusions are caused.

As described above, the water repellent film 200 according to thepresent embodiment includes the first layer 10 having a plurality of thefine protrusions 100, the second layer 20 covering the entire surface ofthe fine protrusions 100 and having a water repellent property, and thethird layer 30 provided on the surface of the first layer 10 on theopposite side of the fine protrusions 100. In addition, when the modulusof elasticity of the first layer 10 is defined as E1, the modulus ofelasticity of the second layer 20 is defined as E2, and the modulus ofelasticity of the third layer 30 is defined as E3, the definition ofE2>E1>E3 is fulfilled. Due to such a configuration, destruction of thefine protrusions 100, that is, abrasions and damages can be prevented.

The external input such as a removal of dirt with a cloth may be broadlydivided into an input in a shear direction substantially along thesurface of the first layer 10, and an input in a compressive directionsubstantially perpendicular to the surface of the first layer. Withregard to the input in the shear direction, the second layer 20 has themodulus of elasticity E2 higher than that of the first layer 10, so asnot to be easily abraded. Further, the input of shear force transmittedto the first layer 10 is absorbed and dispersed. In addition, since thefirst layer 10 has the modulus of elasticity E1 lower than that of thesecond layer 20, the input of shear force to the fine protrusions 100 isflexibly absorbed.

With regard to the input in the compressive direction, the third layer30 having the modulus of elasticity E3 lower than that of the firstlayer 10 mainly receives the input so as to be deformed elastically,thereby preventing destruction of the fine protrusions 100. The firstlayer 10 is required to have a predetermined level of the modulus ofelasticity E1 in view of enhancing a dimensional accuracy at the time ofthe formation of the fine protrusions 100 and preventing the fineprotrusions 100 from scratches of nails. However, when the first layer10 is only provided with the second layer 20 covering the first layerand having the higher modulus of elasticity E2, the first layer 10 ismainly subjected to elastic deformation due to the input in thecompressive direction; on the other hand, the second layer 20 is notelastically deformed very much. In such a case, since the amount ofelastic deformation of the first layer 10 relatively becomes large, itis hard to ensure resistance to abrasion. However, when the third layer30 having the modulus of elasticity E3 lower than that of the firstlayer 10 is provided on the surface of the first layer 10 on theopposite side of the fine protrusions 100, the third layer 30 issubjected to elastic deformation. Accordingly, the amount of elasticdeformation of the first layer 10 or the second layer 20 can bedecreased.

The influence of the inputs in the compressive direction and the sheardirection with respect to the fine protrusions will be furtherexplained. FIGS. 4(a) to 4(c) show water repellent films not providedwith the second layer. In particular, in FIG. 4(b), the modulus ofelasticity E3 of the third layer 30 and the modulus of elasticity E1 ofthe first layer 10 have a relationship of E3>E1. In FIG. 4(c), themodulus of elasticity E3 of the third layer 30 and the modulus ofelasticity E1 of the first layer 10 have a relationship of E1>E3. Asshown in FIG. 4(b), when a load W is applied in the compressivedirection, the first layer 10 is mainly deformed and the third layer 30is not easily deformed since the modulus of elasticity E3 of the thirdlayer 30 is higher than the modulus of elasticity E1 of the first layer10. As a result, the load W is concentrated on the fine protrusions 100,so that the fine protrusions 100 are crushed by the load W (refer to thereference symbol C). On the other hand, as shown in FIG. 4(c), when themodulus of elasticity E3 of the third layer 30 is lower than the modulusof elasticity E1 of the first layer 10, not only the first layer 10 butalso the third layer 30 are deformed, and the load W applied to the fineprotrusions 100 is dispersed. Accordingly, the crush of the fineprotrusions 100 can be prevented.

It is to be noted that, when the second layer is not formed in the waterrepellent film, and particularly when the first layer 10 is made of amaterial such as a resin material as described later having the modulusof elasticity E1, the fine protrusions are easily subjected to abrasionfrom the tips thereof due to continuous inputs in the shear direction.In view of this, the water repellent film according to the presentinvention is provided with the second layer having a high modulus ofelasticity and rigidity in order to improve resistance to abrasion.However, even if the second layer 20 is formed in the film, the fineprotrusions 100 are easily fractured when the modulus of elasticity E3of the third layer 30 is higher than the modulus of elasticity E1 of thefirst layer 10, or when the third layer is not provided, as shown inFIG. 4(d). In other words, since the surface of the second layer isrigid, moment is concentrated on a portion D of a ridge line of the fineprotrusions 100 due to the input in the shear direction (horizontaldirection), and therefore, the fine protrusions 100 are easilyfractured. When the load W is applied in a sliding direction whileevenly coming in contact with the surface of the second layer, thesecond layer is not easily fractured since the surface thereof is rigid.On the other hand, when the load W is applied in a sliding direction notevenly coming in contact with the surface of the second layer, the inputlocally becomes large, and as a result, the fine protrusions 100 arefractured because of brittleness of the second layer 20. However, asdescribed above, when the modulus of elasticity E3 of the third layer 30is lower than the modulus of elasticity El of the first layer 10, thethird layer 30 is deformed, so that the load W applied to the fineprotrusions 100 is dispersed. Accordingly, moment concentrated on thefine protrusions 100 can be prevented, and therefore, the fineprotrusions 100 are not easily fractured.

As described above, since the first layer 10, the second layer 20 andthe third layer 30 share the function with respect to an external inputsuch as a removal of dirt with a cloth, the fracture of the fineprotrusions 100 can be suppressed.

The modulus of elasticity E1 of the first layer 10 is particularlypreferably between 0.1 GPa and 5 GPa, and the modulus of elasticity E2of the second layer 20 is preferably between 50 GPa and 210 GPa. Whenthe modulus of elasticity E1 of the first layer 10 is within theabove-mentioned range, the second layer 20 can sufficiently exert theeffect of dispersing an external input in a shear direction withoutbeing inhibited by the first layer. In addition, when the modulus ofelasticity of the second layer 20 is 50 GPa or more, abrasions of thesecond layer 20 and plastic deformation or fracture of the first layer10 can be surely suppressed. Moreover, when the modulus of elasticity ofthe second layer 20 is 210 GPa or less, brittle damages of the secondlayer 20 due to an external input in a shear direction can be moresurely suppressed.

A thickness T1 of the first layer 10 is preferably between 1 μm and 30μm. When the thickness of the first layer 10 is 1 μm or more, anoccurrence of brittle damages (cracks) of the first layer 10 can beprevented even when the third layer 30 is deformed due to an input in acompressive direction. In addition, when the thickness of the firstlayer 10 is 30 μm or less, a curved surface compliance property can beeasily ensured when the water repellent film 200 is applied to a moldedproduct having a three-dimensional curved surface. Further, moldabilitycan be easily ensured when an active energy beam curable resin is usedas a material of the first layer 10.

A film thickness T2 of the second layer 20 is preferably between 1 nmand 30 nm, more preferably between 3 nm and 20 nm. With regard to thestructure of the fine protrusions 100 having the pitch A of 380 nm orless, the film thickness T2 of the second layer 20 is preferably between3 nm and 10 nm. When the film thickness of the second layer 20 is within30 nm, brittle damages of the second layer 20 can be prevented. Inaddition, when the film thickness is 1 nm or more, the entire fineprotrusions 100 can be evenly covered with the second layer 20.

Examples of the material of the first layer 10 include: thermoplasticresins such as a non-cross-linked acrylic resin, a cross-linked acrylicresin, a cross-linked acrylic-urethane copolymer, a cross-linkedacrylic-elastomer copolymer, a silicone elastomer, polyethylene,polypropylene, cross-linked polyvinyl alcohol, polyvinylidene chloride,polyethylene terephthalate, polyvinyl chloride, polycarbonate, modifiedpolyphenylene ether, polyphenylene sulfide, polyether ether ketone, aliquid crystal polymer, fluororesin, polyarylate, polysulfone, polyethersulfone, polyamide imide, polyether imide, and thermoplastic polyimide;styrene elastomers such as polystyrene; urethane elastomers; siliconeelastomers; and various gel materials.

Examples of the material of the second layer 20 include: transparentinorganic materials such as glass, silicon oxide, and aluminum oxide;and ceramic materials such as silicon nitride, magnesium oxide, titaniumoxide, indium oxide, niobium oxide, zirconium oxide, zinc oxide, ITO(indium tin oxide), and barium titanate. In particular, hafnia (hafniumoxide, HfO₂) has a contact angle of 90 degrees or more. Therefore, ahigh water repellent property can be exerted even if the surface of thesecond layer is not subjected to chemical treatment in order to have awater repellent property.

When a contact angle of the material of the second layer 20 with respectto water droplets is 90 degrees or more, a superhydrophobic state thatfar exceeds the contact angle of the material itself of the second layer20 is obtained (Cassie theory) because of an increase of the surfacearea of the water repellent film and an effect of trapping air in gaps22 between the fine protrusions 100 adjacent to each other, as shown inFIG. 5. In order to further effectively exert the superhydrophobicstate, the contact angle of the material itself of the second layer 20with respect to water droplets is preferably 100 degrees or more, morepreferably 110 degrees or more. Especially when the material having thecontact angle of 110 degrees or more is used for the second layer of thefine protrusions 100, the contact angle is amplified by the fineprotrusions 100 so that the contact angle becomes 140 degrees or more,thereby improving a water repellent property to such a degree that waterdroplets are hardly adhered to the surface of the second layer 20.

In order to achieve such a water repellent effect, the contact angle maybe controlled by selecting the material of the second layer 20 itself.As a method of controlling the contact angle more simply, a method ofallowing a water repellent material having reactivity with the materialof the second layer to chemically adhere to or react with a surface 21of the second layer 20 may be used. The method of controlling thecontact angle is not particularly limited as long as a plurality of thefine protrusions 100 are not blocked by the water repellent material.When the method of applying the water repellent material diluted with asolvent to the surface 21 of the second layer 20 is used, the waterrepellent material can be fixed to the surface 21 of the second layer20.

Examples of the water repellent material applied to the surface 21 ofthe second layer 20 include silicone compounds such asCH₃—(Si(CH₃)₂—O)_(n)—Si(CH₃)₂OCH₃ (n>13; contact angle of 95 to 105degrees), CH₃—(Si(CH₃)₂—O)_(n)—SiCH₃(OCH₃)₂ (n>13; contact angle of 95to 105 degrees), CH₃—(Si(CH₃)₂—O)_(n)—Si(OCH₃)₃ (n>13; contact angle of95 to 105 degrees), CH₃—(Si(CH₃)₂—O)_(n)—Si(OC₂H₅)₃ (n>13; contact angleof 95 to 105 degrees),CH₃—(Si(CH₃)₂—O)_(n)—Si(CH₃)₂(CH₂)₃OCH₂CH(OH)CH₂NH(CH₂)₃Si(OCH₃)₃ (n>13;contact angle of 95 to 105 degrees),(CH₃—(Si(CH₃)₂—O)_(n)—Si(CH₃)₂(CH₂)₃OCH₂CH(OH)CH₂)₂N(CH₂)₃Si(OCH₃)₃(n>13; contact angle of 95 to 105 degrees), CH₃—(Si(CH₃)₂—O)_(n)—Si(OH)₃(n>13; contact angle of 95 to 105 degrees),CH₃—(Si(CH₃)₂—O)_(n)—Si(CH₃)₂Cl (n>13; contact angle of 95 to 105degrees), CH₃—(Si(CH₃)₂—O)_(n)—Si(CH₃)₂(CH₂)₂SiCH₃Cl₂ (n>13; contactangle of 95 to 105 degrees), CH₃—(Si(CH₃)₂—O)_(n)—SiCl₃ (n>13; contactangle of 95 to 105 degrees), CH₃—(Si(CH₃)₂—O)_(n)—Si(OCOCH₃)₃ (n>13;contact angle of 95 to 105 degrees), CH₃—(Si(CH₃)₂—O)_(n)—Si(NCO)₃(n>13; contact angle of 95 to 105 degrees),CH₃—(Si(CH₃)₂—O)_(n)—Si(CH₃)₂(CH₂)₃O(CH₂)₃OCONHSi(NCO)₃ (n>13; contactangle of 95 to 105 degrees),Rf-(CH₂)₂—(Si(CH₃)₂—O)_(n)—Si(CH₃)₂(CH₂)₃OCH₂CH(OH)CH₂NHSi(OCH₃)₃ (n>13;contact angle of 95 to 115 degrees), and(Rf-(CH₂)₂—(Si(CH₃)₂—O)_(n)—Si(CH₃)₂(CH₂)₃OCH₂CH(OH)CH₂)₂N(CH₂)₃Si(OCH₃)₃(n>13; contact angle of 95 to 115 degrees) (Rf is CF₃—(CF₃)_(m)—, orCF₃—(OCF₂)_(m): m=1 to 20). In addition, a material obtained by changinga substituent group such as Teflon (registered trademark) and theabove-mentioned silane compound to isocyanate may also be used.

When the water repellent film according to the present invention is usedin applications in contact with liquid other than water, such as anobservation window panel of a reactor vessel or a distillation column invarious types of plant equipment, and a lens surface of an endoscope, acontact angle with respect to contacting liquid is preferably set at 90degrees or more by surface treatment or the like depending on theapplications.

As shown in FIG. 1, the water repellent film 200 according to thepresent invention includes the third layer 30 in contact with the firstlayer 10 on the opposite side of the fine protrusions 100. In addition,the third layer 30 may be provided with an adhesive agent on theopposite side of the first layer 10 according to the applications of thewater repellent film. When a water repellent film is used for anantireflection application, both surfaces of a transparent material arerequired to be provided with fine protrusions. In the present invention,both surfaces of the third layer 30 made of a transparent material areprovided with the first layer 10 and the second layer 20 symmetrically,so that an antireflection effect can be obtained.

The modulus of elasticity E3 of the third layer 30 is required to belower than the modulus of elasticity E1 of the first layer 10. Examplesof the material used for the third layer 30 include general-purposeresin films and engineering plastic films. More specific examples of thematerial to be used include methacrylic films; polyolefin films such aspolyethylene and polypropylene; polycarbonate films; polyester filmssuch as polyethylene terephthalate (PET), polyethylene naphthalate(PEN), and fluorene derivatives; vinyl chloride films; silicone films;polyvinyl alcohol (PVA) films; ethylene vinyl acetate copolymer (EVA)films; cellulose films; and amide films. When the water repellent filmis used in a portion in which further transparency is required, atransparent third layer is selected. A material of the transparent thirdlayer is preferably methacrylic films, polycarbonate films, or PETfilms, more preferably methacrylic films or PET films.

When the first layer 10 has a thickness barely able to preventbrittleness, the third layer 30 functions to support rigidity and filmintensity of the first layer 10. In addition, when the modulus ofelasticity of the third layer is controlled to be lower than that of thefirst layer, the third layer is more easily deformed due to an externalinput in a compressive direction compared to the first layer. Therefore,an input to the fine protrusions 100 can be absorbed.

A thickness T3 of the third layer 30 is not particularly limited as longas the third layer is thick sufficient to comply with athree-dimensional curved surface or sufficient to be molded. However,the thickness T3 of the third layer 30 is preferably thicker than thethickness of the first layer 10. Due to such a thickness, the thirdlayer 30 is more easily deformed than the first layer, and an input tothe fine protrusions 100 in a compressive direction can be absorbed.When considering processability of molding and adhesion in addition tosuch an action, the thickness T3 of the third layer 30 is preferablyapproximately between 20 μm and 250 μm, more preferably between 25 μmand 200 μm, most preferably between 25 μm and 70 μm. When the thicknessT3 of the third layer 30 is within the range of 20 μm to 200 μm, thedeformation amount of the third layer 30 is appropriately decreased whena load in a compressed direction is input to the water repellent film200. Accordingly, an uneven contact of friction elements at the time offriction input is not caused, a load is uniformly dispersed, andtherefore, the fine protrusions 100 are not easily abraded.

The modulus of elasticity E3 of the third layer 30 is at most 6 GPa whenconsidering the type of the material described above. Therefore, withregard to deformation, a variation of the thickness of the third layer30 is more influential than the first layer 10. In addition, in view ofhandling of a stacked film such as the water repellent film 200according to the present invention, and in view of damages of the thirdlayer at the time of compressive deformation, an elongation at breakε_(max) of the third layer 30 is preferably 50% or more. Note that, theupper limit of the elongation at break ε_(max) of the third layer 30 isnot particularly limited; however, the upper limit may be 500% or less.

[Method for Manufacturing Water Repellent Film]

Hereinafter, a method for manufacturing the water repellent filmaccording to the present invention will be explained. In the waterrepellent film according to the present invention, a film to be thethird layer 30 is prepared first. Then, the film is provided with thefine protrusions 100 so as to form the first layer 10. A method ofproviding the fine protrusions 100 on the first layer 10 is notparticularly limited. For example, a method of forming the fineprotrusions 100 directly on the first layer is used. Further, a methodof pressing a concave-convex molding die having a fine protrusionpattern to a thin film obtained by applying a material easily molded tothe film prepared first so as to transfer the fine protrusion pattern tothe thin film is used. As a result, the fine protrusions 100 are formed.

More specifically, a film composed of materials of the first layer andthe third layer produced by a known method is prepared. Then, a moldingdie to form numerous fine protrusions is prepared, and the molding dieand the film composed of materials of the first layer and the thirdlayer are pressed relatively while heating one of or both of the moldingdie and the film. Therefore, the fine protrusions 100 can be formed onthe surface of the first layer.

In addition, an active energy beam curable resin is applied on the filmto be the third layer. Then, a portion between the molding die and thefilm to be the third layer is irradiated with an active energy beamwhile interposing the active energy beam curable resin, so that theresin is cured. An example of the active energy beam curable resin maybe an ultraviolet beam curable resin.

After the first layer having the fine protrusions 100 is formed by theabove-described methods, the second layer 20 is formed by aconventionally known method. Examples of the method of producing thesecond layer 20 include a Langmuir-Blodgett method (LB method), aphysical vapor deposition method (PVD method), a chemical vapordeposition method (CVD method), a self-organization method, a sputteringmethod, a vapor polymerization method, and an evaporation method.

Further, as described above, when a water repellent material is fixed tothe second layer, the water repellent material that is diluted with asolvent is applied on the second layer and then dried. In order topromote the reaction of the second layer with the water repellentmaterial after the application of the water repellent material, heattreatment may be carried out as necessary.

[Molded Product Including Water Repellent Film]

A molded product (component) including the water repellent filmaccording to the present invention may be preferably used for a displaydevice that is required to have an antireflection function on the frontsurface thereof and is subjected to water such as rain and greasy dirt.Examples of the molded product include meter panels and window panelsfor vehicles and motor cycles, mobile devices such as a mobile phone andan electronic organizer, signs, and watches. A type of the displaydevice is not particularly limited, and a system in which a mechanicaldisplay and lighting are combined such as an analog meter may beincluded. Moreover, a system, such as a digital meter and a monitor,using a back light and a light-emitting surface such as a liquidcrystal, light-emitting diode (LED) and electroluminescence (EL), and asystem using a reflective liquid crystal such as a mobile device mayalso be included.

Such a molded product is mainly used in places to be subjected to light.Therefore, an ultraviolet absorbing agent, an antioxidant, a radicalscavenger, and the like may be added to the first layer and the thirdlayer in order to prevent deterioration by light. In addition, a blueingagent and a fluorescent pigment for offsetting yellowing caused by resindeterioration may also be used.

A method for manufacturing the molded product including the waterrepellent film is not particularly limited as long as the film can beattached to the surface of the molded product. A method of attaching thefilm by hands while applying heat on a curved surface may be used. Inaddition, a laminator and the like may be used when the molded productdoes not have a curved surface. Further, the water repellent filmaccording to the present invention may be attached to the molded productby use of an adhesive agent as necessary.

When the water repellent film according to the present invention isincorporated in a display device, the provision of the film on the frontsurface of the display device is most effective. In addition, aconventional antireflection means may be applied to the surface of thethird layer on the opposite side of the first layer in the waterrepellent film according to the present invention. Examples of theconventional antireflection means include a means of applying anantireflection structure only provided with fine protrusions with apitch not more than a wavelength of light, and a means of allowingreflected light from the surface of the thin film in which the thicknessof the antireflection layer is controlled and reflected light from theattachment surface of the third layer to interfere with each other, soas to decrease reflection.

When it is assumed that the water repellent film according to thepresent invention is attached to a three-dimensional curved surface, theproperties required for the third layer and the first layer aredetermined according to a radius of curvature of the three-dimensionalcurved surface. In particular, the important property in molding andprocessing of the film for the three-dimensional curved surface is amaximum value of elongation at break B. That is, as shown in FIG. 6, itis assumed that the thickness of the first layer 10 is T1, the thicknessof the third layer 30 is T3, and the thickness of an adhesion layer 40applied on the surface of the third layer 30 on the opposite side of thefirst layer 10 is T4. When the water repellent film 200 is attached to aconvex surface of a radius of curvature R of a component 50, the waterrepellent film 200 is curved on the basis of an adhesion surface 41 ofthe adhesion layer 40. Then, one-dimensional elongation of the uppermostsurface of the first layer 10 that is the most elongated layer withrespect to a distance R (radius of curvature) from the center O ofcurvature to the adhesion surface 41 is calculated. Thus, the maximumvalue of elongation at break B can be calculated according to theformula 1. Therefore, at least the material of the first layer 10 isrequired to have an elongation at break higher than the maximum value ofelongation at break B.

$\begin{matrix}{B = {\sqrt{\frac{\left( {R + {T\; 1} + {T\; 3} + {T\; 4}} \right)^{2}}{R^{2}}} = \frac{R + {T\; 1} + {T\; 3} + {T\; 4}}{R}}} & \left\lbrack {{Math}\mspace{14mu} 1} \right\rbrack\end{matrix}$

On the other hand, when the water repellent film 200 is attached to aconcave surface of the component 50, the adhesion layer 40 is to beelongated on the basis of the uppermost surface of the first layer 10since the first layer 10 has the higher modulus of elasticity than thethird layer 30 or the adhesion layer 40. However, the adhesion layer 40is not fractured since the elongation at break of the adhesion layer 40is much larger than that of the first layer 10.

As described above, the water repellent film according to the presentinvention includes the first layer, the second layer and the third layerhaving the above-described characteristics. Therefore, the waterrepellent film has an excellent resistance to abrasion while ensuring ahigh water repellent property. Further, since the pitch between the fineprotrusions is controlled to be 380 nm or less, reflection of visiblelight can be decreased to an extremely low level. Accordingly, when thewater repellent film is applied to a component for a vehicle and otherapplications, such as a meter cover and a windshield, reflection ofsurrounding sceneries or interiors on the film can be prevented whileensuring a water repellent property.

When the water repellent film according to the present invention is usedfor window glass or an analog meter, all of the first layer, the secondlayer and the third layer included in the water repellent film arepreferably transparent. On the other hand, when the water repellent filmis used for a digital meter or a screen of a car navigation system, thefirst layer and the third layer may have opaque areas for the purpose ofadding an anti-glare function and a depolarization function.

EXAMPLES

Hereinafter, the present invention will be further explained in detailwith reference to examples. However, the scope of the present inventionis not limited to those examples.

Examples 1 to 19

First, a film to be the third layer and an ultraviolet curable monomerfor forming the first layer were prepared for respective Examples 1 to 3and 8 to 19, as shown in Table 1. Note that, “flexible acrylic resin” inTable 1 is ACRYPLEN (registered trademark) manufactured by MitsubishiRayon Co., Ltd. Next, the ultraviolet curable monomer was applied to onesurface of the film to be the third layer. Then, a metal mold forforming fine protrusions having dimensions described in Table 2 waspressed against the monomer, followed by irradiation of ultraviolet fromthe film to be the third layer, so that the monomer was cured.Subsequently, the film was separated from the metal mold, so as toprepare the film provided with the fine protrusions on the first layerfor the respective examples. Thereafter, the second layer described inTable 1 was applied to the film of the respective examples by use of asputtering method.

With regard to Example 4, a film to be the third layer and a urethanegel (product name: PANDEX (registered trademark) <two-component curabletype>, manufactured by DIC Corporation) for forming the first layer wereprepared, as shown in Table 1. Next, the gel solution was applied to ametal mold for forming fine protrusions having dimensions described inTable 2, and the metal mold was pressed against the film to be the thirdlayer, followed by curing at 100° C. for one hour. Then, the film wasseparated from the metal mold, so as to prepare the film provided withthe fine protrusions on the first layer. Thereafter, the second layerdescribed in Table 1 was applied to the film by use of a sputteringmethod.

With regard to Example 5, a film to be the third layer and a siliconegel (product name: KE-1051, manufactured by Shin-Etsu Chemical Co.,Ltd.) for forming the first layer were prepared, as shown in Table 1.Next, the silicone gel solution was applied to a metal mold for formingfine protrusions having dimensions described in Table 2, and the metalmold was pressed against the film to be the third layer, followed bycuring at 100° C. for one hour. Then, the film was separated from themetal mold, so as to prepare the film provided with the fine protrusionson the first layer. Thereafter, the second layer described in Table 1was applied to the film by use of a sputtering method.

With regard to Examples 6 and 7, a film to be the third layer wasprepared. In addition, for the formation of the first layer, a mixturesolution of 5% of polycaprolactone (product name: PCL-220, manufacturedby Daicel Chemical Industries, Ltd.) and 95% of 4,4′-diphenylmethanediisocyanate (product name: Millionate MT, manufactured by NipponPolyurethane Industry Co., Ltd.) was prepared. Next, the mixturesolution was applied to a metal mold for forming fine protrusions havingdimensions described in Table 2, and the metal mold was pressed againstthe film to be the third layer, followed by curing at 130° C. for onehour. Then, the film was separated from the metal mold, so as to preparethe film provided with the fine protrusions on the first layer for therespective examples. Thereafter, the second layer described in Table 1was applied to the film for the respective examples by use of asputtering method.

With regard to Examples 1 to 8 and 15 to 19, the surface of the secondlayer was subjected to surface treatment usingperfluoroethertrimethoxysilane as a water repellent material. Morespecifically, a solution obtained by dilutingperfluoroethertrimethoxysilane with hydrofluoroether (product name:HFE-7100, manufactured by Sumitomo 3M Limited) by 0.1% was prepared.Next, the film provided with the second layer for the respectiveexamples was impregnated with this solution, and pulled up at a pull-uprate of 10 mm/sec, so as to apply the solution to the surface of thesecond layer. Thereafter, the film applied with the solution was driedat 100° C. for one hour, followed by fixing water repellent groups tothe surface of the second layer provided on fine protrusions, therebyobtaining the water repellent film for the respective examples. Notethat, perfluoroethertrimethoxysilane is indicated by a reference symbol“a” in Table 2.

With regard to Examples 9, 11 and 13, the second layer was subjected tothe same surface treatment using(heptadecafluoro-1,1,2,2-tetrahydrodecyl) trimethoxysilane (manufacturedby AZmax Co., Ltd.). Note that,(heptadecafluoro-1,1,2,2-tetrahydrodecyl)trimethoxysilane is indicatedby a reference symbol “b” in Table 2.

With regard to Examples 10 and 14, the second layer was subjected to thesame surface treatment using (heptafluorooctyl)trimethoxysilane(manufactured by AZmax Co., Ltd.). Note that,(heptafluorooctyl)trimethoxysilane is indicated by a reference symbol“c” in Table 2. With regard to Example 12, the second layer made ofhafnia was not subjected to surface treatment.

Comparative Example 1

First, a fine protrusion pattern was transferred to PVA, so as toprepare a replica mold of fine protrusions having dimensions describedin Table 2. Next, polysiloxane was poured into the replica mold. Then,the third layer subjected to corona treatment was pressed against thepolysiloxane, and heated at 100° C. for 24 hours, followed by keeping atconstant temperature and humidity at 100° C. and at 60% humidity for 24hours, thereby forming a film composed of the first layer having thefine protrusions and the third layer. In this comparative example, thefilm was not provided with the second layer.

Comparative Example 2

A film composed of the first layer and the third layer was prepared inthe same manner as Example 3. However, the film was not provided withthe second layer in this example.

The materials, properties and thicknesses of the first layer to thirdlayer for the respective examples and comparative examples are shown inTable 1. The respective values of each modulus of elasticity in Table 1were measured according to the method described in JIS K 6911 ofJapanese Industrial Standard. The elongation at break was measuredaccording to the method described in JIS K 7161 (ISO 527). In addition,the thicknesses of the respective layers, and the pitches, heights andtip diameters of the fine protrusions were measured using a scanningelectron microscope (SEM), respectively.

TABLE 1 Third Layer First Layer Second Layer Modulus of ElongationModulus of Modulus of Contact Elasticity Thickness at Break ElasticityThickness Elasticity Thickness Angle Material (GPa) (μm) (%) Material(GPa) (μm) Material (GPa) (μm) (°) Example 1 PET 3.5 25 150 Cross- 3.8 8Silicon 70 10 21 linked Oxide PMMA Example 2 PET 3.5 50 150 Cross- 4 5Zirconium 210 15 25 linked Oxide PMMA Example 3 PET 3.5 100 150 Cross- 55 Zirconium 210 30 25 linked Oxide PMMA Example 4 Silicone 0.05 100 300Urethane 0.1 30 Silicon 50 10 21 Gel Oxide Example 5 Silicone 0.1 100250 Silicone 0.3 30 Silicon 60 10 21 Gel Oxide Example 6 Silicone 0.3200 200 Urethane 0.7 30 Silicon 70 10 21 Elastomer Oxide Example 7Siheone 0.3 200 200 Urethane 0.7 30 Silicon 80 10 21 Elastomer OxideExample 8 Flexible 2 50 50 Cross- 2.8 15 Silicon 70 10 21 Acrylic linkedOxide Resin PMMA Example 9 Flexible 1.2 50 50 Cross- 4 10 Aluminum 70 521 Acrylic linked Oxide Resin PMMA Example 10 Flexible 1.3 100 50 Cross-4 10 Aluminum 65 5 21 Acrylic linked Oxide Resin PMMA Example 11Flexible 0.9 100 50 Cross- 4.5 10 Aluminum 70 10 21 Acrylic linked OxideResin PMMA Example 12 Flexible 0.9 100 50 Cross- 4.5 10 Hafnia 70 5 90Acrylic linked Resin PMMA Example 13 Acrylic 2.8 200 40 Cross- 5 8Zirconium 210 15 25 Resin linked Oxide PMMA Example 14 Acrylic 3 200 40Cross- 5 1 Zirconium 210 30 25 Resin linked Oxide PMMA Example 15Flexible 2 100 50 Cross- 3.8 6 Silicon 70 5 15 Acrylic linked OxideResin PMMA Example 16 Flexible 2 100 50 Cross- 2.8 8 Silicon 70 5 15Acrylic linked Oxide Resin PMMA Example 17 Flexible 1.9 200 50 Cross-2.8 10 Silicon 70 5 15 Acrylic linked Oxide Resin PMMA Example 18Flexible 1.9 250 50 Cross- 2.8 10 Silicon 70 5 15 Acrylic linked OxideResin PMMA Example 19 Flexible 1.9 250 50 Cross- 2.8 10 Silicon 70 5 15Acrylic linked Oxide Resin PMMA Comparative PET 3.5 25 150 SiOx 65 10 —— — — Example 1 Comparative PET 3.5 50 150 PMMA 2 5 — — — — Example 2

TABLE 2 Fine Protrusions Surface Treatment Tip Contact Pitch HeightDiameter Angle Configuration (nm) (nm) (nm) Material (°) Example 1Circular Truncated 100 200 5 a 115 Cone Example 2 Circular Truncated 380500 30 a 115 Cone Example 3 Circular Truncated 5000 5000 200 a 115 ConeExample 4 Circular Truncated 250 250 15 a 115 Cone Example 5 CircularTruncated 250 500 10 a 115 Cone Example 6 Circular Truncated 300 380 20a 115 Cone Example 7 Circular Truncated 300 300 10 a 115 Cone Example 8Circular Truncated 100 100 5 a 115 Cone Example 9 Circular Truncated 100200 7 b 110 Cone Example 10 Circular Truncated 100 200 5 c 108 ConeExample 11 Circular Truncated 200 200 5 b 110 Cone Example 12 CircularTruncated 200 200 5 — — Cone Example 13 Hemisphere 2000 2000 0 b 110Example 14 Truncated 5000 3000 100 c 108 Square Pyramid Example 15 BellShape 100 200 — a 115 Example 16 Bell Shape 100 200 — a 115 Example 17Bell Shape 100 200 — a 115 Example 18 Bell Shape 100 200 — a 115 Example19 Frustum Shape 100 200 — a 115 Comparative Circular Truncated 100 2005 — — Example 1 Cone Comparative Circular Truncated 300 600 15 — —Example 2 Cone

The fine films of Examples 1 to 19 and Comparative Examples 1 to 2manufactured as described above were used for the evaluations of anabrasion resistance, an antireflection property and a water repellentproperty according to the following evaluation methods.

[Test Method for Evaluation of Abrasion Resistance]

The respective films were reciprocated 200 times using a traverseabrasion testing machine under the following conditions, followed byvisually confirming damages of the films. In Table 3, the case in whichno damage was visually confirmed is indicated by “circle”, the case inwhich some damages were visually confirmed but acceptable is indicatedby “triangle”, and the case in which apparent damages were confirmed andan white-colored appearance was observed is indicated by “cross”.

Friction cloth: Canvas cloth (JIS L 3102)

Load: 9.8 kPa

Stroke length: 100 mm

Friction rate: 30 reciprocation/minute

[Test Method for Evaluation of Antireflection Property]

The examples having the pitches of the fine protrusions of 380 nm orless were used to measure the visible light reflectance at 0 degreeusing a goniophoto meter (manufactured by Otsuka Electronics Co., Ltd.).In table 3, the case in which an arithmetic average value of the visiblelight reflectance is 0.5% or less is indicated by “circle”, the case inwhich the arithmetic average value is more than 0.5% to 1% or less isindicated by “triangle”, and the case in which the arithmetic averagevalue is more than 1% is indicated by “cross”. In this test method,since reflection was caused from the rear surface of the water repellentfilm of the respective examples, the rear surface was blacked out so asto measure the reflectance.

[Test Method for Evaluation of Water Repellent Property]

After the test for the evaluation of the abrasion resistance, the waterrepellent property was evaluated on a scale of 1 to 5 based on thefollowing criteria according to the method specified by JIS L 1092 usinga spray tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.).

1: Get entire surface wet

2: Get surface wet without maintaining spherical droplet shape onsurface

3: Have spherical droplets adhering to surface

4: Have fine spherical droplets slightly adhering to surface

5: Have no spherical droplet

The respective evaluation results are shown in Table 3. According to theresults, it was confirmed that the abrasion resistance of the fineprotrusions was improved by increasing the modulus of elasticity of thesecond layer more than the first layer. In addition, it was alsoconfirmed that the abrasion resistance was improved by decreasing themodulus of elasticity of the third layer less than the first layer.Further, according to the examples, it was confirmed that a particularlyexcellent water repellent property was exerted when the contact angle inthe fine protrusions of the surface of the second layer or the contactangle after surface treatment of the second layer was high.

TABLE 3 Anti- Water Abrasion reflection Repellent Resistance PropertyProperty Note Example 1 ◯ ◯ 5 Surface Treatment Example 2 ◯ ◯ 5 SurfaceTreatment Example 3 ◯ — 5 Surface Treatment Example 4 ◯ ◯ 5 SurfaceTreatment Example 5 ◯ ◯ 5 Surface Treatment Example 6 ◯ ◯ 5 SurfaceTreatment Example 7 ◯ ◯ 5 Surface Treatment Example 8 ◯ ◯ 5 SurfaceTreatment Example 9 ◯ ◯ 5 Surface Treatment Example 10 ◯ ◯ 5 SurfaceTreatment Example 11 ◯ ◯ 5 Surface Treatment Example 12 ◯ ◯ 5 No SurfaceTreatment Example 13 ◯ — 5 Surface Treatment Example 14 ◯ — 5 SurfaceTreatment Example 15 ◯ ◯ 5 Surface Treatment Example 16 ◯ ◯ 5 SurfaceTreatment Example 17 ◯ ◯ 5 Surface Treatment Example 18 ◯ ◯ 5 SurfaceTreatment Example 19 ◯ ◯ 5 Surface Treatment Comparative X — — — Example1 Comparative X — 1 — Example 2

Although the present invention has been described above by reference tothe embodiment and the examples, the present invention is not limited tothose, and it will be apparent to these skilled in the art that variousmodifications and improvements can be made.

INDUSTRIAL APPLICABILITY

In the water repellent film according to the present invention, therelationships among the modulus of elasticity E1 of the first layer, themodulus of elasticity E2 of the second layer, and the modulus ofelasticity E3 of the third layer are defined as E2>E1>E3. Therefore, awater repellent film having excellent resistance to abrasion, in which afine structure is not easily abraded and damaged by an external frictionforce such as a rain impact and a removal of dirt with a cloth on thesurface of the film, and a component for a vehicle including the filmcan be provided.

REFERENCE SIGNS LIST

A Pitch

10 First layer

20 Second layer

30 Third layer

100 Fine protrusions

200 Water repellent film

1. A water repellent film, comprising: a first layer having a pluralityof fine protrusions on a surface thereof; a second layer covering thefine protrusions and having a water repellent property; and a thirdlayer provided on a surface of the first layer on an opposite side ofthe fine protrusions, wherein when a modulus of elasticity of the firstlayer is defined as El, a modulus of elasticity of the second layer isdefined as E2, and a modulus of elasticity of the third layer is definedas E3, a definition of E2>E1>E3 is fulfilled.
 2. The water repellentfilm according to claim 1, wherein a pitch of the fine protrusions is380 nm or less.
 3. The water repellent film according to claim 1,wherein a height of the fine protrusions is 100 nm or more.
 4. The waterrepellent film according to claim 1, wherein a pitch of the fineprotrusions is 150 nm or less.
 5. The water repellent film according toclaim 1, wherein a height of the fine protrusions is 600 nm or less. 6.The water repellent film according to claim 1, wherein a thickness ofthe third layer is larger than a thickness of the first layer.
 7. Thewater repellent film according to claim 1, wherein a thickness T3 of thethird layer is 20 μm<T3<250 μm.
 8. The water repellent film according toclaim 1, wherein an elongation at break E_(max) of the third layer is50% or more.
 9. The water repellent film according to claim 1, whereinthe modulus of elasticity of the first layer is between 0.1 GPa and 5GPa, and the modulus of elasticity of the second layer is between 50 GPaand 210 GPa.
 10. The water repellent film according to claim 1, whereinthe fine protrusions are formed into a cone or pyramid shape, or afrustum shape.
 11. The water repellent film according to claim 1,wherein the thickness of the first layer is between 1 μm and 30 μm, anda thickness of the second layer is between 1 nm and 30 nm.
 12. Acomponent for a vehicle comprising the water repellent film according toclaim
 1. 13. The water repellent film according to claim 1, wherein thefirst layer includes a material selected from the group consisting of athermoplastic resin, a styrene elastomer, a urethane elastomer, asilicone elastomer, and gel material, and wherein the thermoplasticresin includes a material selected from the group consisting of anon-cross-linked acrylic resin, a cross-linked acrylic resin, across-linked acrylic-urethane copolymer, a cross-linkedacrylic-elastomer copolymer, a silicone elastomer, cross-linkedpolyvinyl alcohol, polyvinylidene chloride, polyethylene terephthalate,polyvinyl chloride, polycarbonate, modified polyphenylene ether,polyphenylene sulfide, polyether ether ketone, a liquid crystal polymer,fluororesin, polyarylate, polysulfone, polyether sulfone, thermoplasticpolyimide, polyamide imide and polyether imide.
 14. The water repellentfilm according to claim 1, wherein the second layer includes a materialselected from the group consisting of a transparent inorganic and aceramic material, wherein the transparent inorganic includes a materialselected from the group consisting of glass, silicon oxide, and aluminumoxide, and wherein the ceramic material includes a material selectedfrom the group consisting of silicon nitride, magnesium oxide, titaniumoxide, indium oxide, niobium oxide, zirconium oxide, zinc oxide, ITO,barium titanate, and hafnia.
 15. The water repellent film according toclaim 1, wherein the third layer includes a material selected from thegroup consisting of a methacrylic film, a polyolefin film, apolycarbonate film, a polyester film, a vinyl chloride film, a siliconefilm, a polyvinyl alcohol (PVA) film, an ethylene vinyl acetatecopolymer (EVA) film, a cellulose film, and an amide film, wherein thepolyolefin film includes any one of polyethylene and polypropylene, andwherein the polyester film includes a material selected from the groupconsisting of polyethylene terephthalate (PET), polyethylene naphthalate(PEN), and fluorene derivatives.